CVE-2025-48887: vLLM regular expression denial of service in pythonic tool parser

Summary

vLLM, an inference and serving engine for large language models (LLMs), contains a Regular Expression Denial of Service (ReDoS) flaw in `vllm/entrypoints/openai/tool_parsers/pythonic_tool_parser.py` in versions 0.6.4 up to but excluding 0.9.0. The tool call detection regex uses multiple nested quantifiers, optional groups and inner repetitions, so an attacker can trigger catastrophic backtracking, severely degrading performance or making the service unavailable.

Mitigation

Version 0.9.0 contains a patch for the issue.

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

• vllmPyPILLM dependency since 2023-08-25 · 15 tracked dependents

Topics

• Inference infrastructure

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